Convective / Storm Discussion - 23rd August onwards 2013

[Coast]

Just to show progression of ideas in the models, GFS is currently touting this for Friday:

 

 

Then Saturday:

 

 

 

and Sunday:

 

 

 

So a slow transition to possible isolated events and in areas that will keep some people smiling :winky: Onwards to the weekend then!

[Team Jo]

Soggy Duxford I fear

[Guest William Grimsley]

Just to show progression of ideas in the models, GFS is currently touting this for Friday:

 

 

Then Saturday:

 

 

 

and Sunday:

 

 

 

So a slow transition to possible isolated events and in areas that will keep some people smiling Onwards to the weekend then!

It looks like there might be quite a bit of thunderstorm activity around the S Coasts of SW England on Saturday and Sunday. It will defintely keep me smiling.

[Convective]

Something is lurking. Believe me it is. The charts are begging to show us a plume but just can't. Still time this year for some good'ns! 

 

Saturday onwards look bang on for me!

[Guest William Grimsley]

Saturday onwards look bang on for me!

The Isle of Man is forecast nothing like SW England!

[Guest William Grimsley]

Friday, Monday and Tuesday are being shown as quite wet on the UK precipitation chart!

 

UK precipitation. Valid: Fri 06/09 9:00.

 

 

UK precipitation. Valid: Mon 09/09 9:00.

 

 

UK precipitation. Valid: Tue 10/09 12:00.

 

Edited September 3, 2013 by William Grimsley

[Convective]

The Isle of Man is forecast nothing like SW England!

 

Really..? Looks alright! Best time of year around here! 

 

 

[Guest William Grimsley]

Really..? Looks alright! Best time of year around here! 

 

 

That's only 1 day.

[Guest William Grimsley]

It's looking promising for Tuesday and Wednesday for SW England next week, too!

 

UK CAPE+Lifted Index. Valid: Tue 10/09 12:00.

 

 

UK CAPE+Lifted Index. Valid: Wed 11/09 12:00.

 

[A.J]

a note of caution....the GFS precip charts are notoriously unreliable and prone to a high error precentage value so absolutely no point whatsoever looking at them post T48

 

 

 

...and the same goes for GFS CAPE/LI charts...take with a very large pinch of salt until moves into the hi-res phase (t48 - t0) to save disappointment

Edited September 3, 2013 by ajpoolshark

[Guest William Grimsley]

a note of caution....the GFS precip charts are notoriously unreliable and prone to a high error precentage value so absolutely no point whatsoever looking at them post T48

yeah I've noticed that

[A.J]

you're much better off looking at the hi-res models for more accurate and reliable figures for those parameters such as NMM, NAE & HIRLAM

[Guest William Grimsley]

you're much better off looking at the hi-res models for more accurate and reliable figures for those parameters such as NMM, NAE & HIRLAM

ok but only the NMM charts are available on Netweather and that's Netweather Extra!

Edited September 3, 2013 by William Grimsley

[The PIT]

Unfortunately the NMM has been reliable for me either when I've used in the past. Gets it wrong probably more times than it gets it right.

[Coast]

Unfortunately the NMM has been reliable for me either when I've used in the past. Gets it wrong probably more times than it gets it right.

 

Do you mean it is or it isn't reliable? In the shorter term it's been quite good for me on convective issues.  

[Coast]

GFS shifting any potential for Friday and beyond around it a bit, as models like to do!

 

 

Eyes and ears out to sea?

 

 

 

 

 

At this rate it just looks like rain and the Tstorm potential is either waning or moving offshore if GFS has a grip of things.

[Guest William Grimsley]

GFS shifting any potential for Friday and beyond around it a bit, as models like to do!

 

 

Eyes and ears out to sea?

 

 

 

 

 

At this rate it just looks like rain and the Tstorm potential is either waning or moving offshore if GFS has a grip of things.

Yeah it looks like most of the thunderstorm is over the Irish Sea with just rain over S England.

[Guest William Grimsley]

It's looking very active for SW England, this weekend! I can't wait to see this happen!

 

UK CAPE+Lifted Index. Valid: Sat 07/09 15:00.

 

 

UK CAPE+Lifted Index. Valid: Sun 08/09 15:00.

 

 

This looks very promising, too! Except I'm just coming out of school then so that probably wouldn't go down well!

 

UK CAPE+Lifted Index. Valid: Tue 10/09 15:00.

 

Edited September 4, 2013 by William Grimsley

[Weather-history]

Can see a line of altocumulus castellanus to the west over the Irish Sea.

[Guest William Grimsley]

Can see a line of altocumulus castellanus to the west over the Irish Sea.

Lovely stuff. There is some crossing NW Devon, now.

[Supacell]

Possibly a brave call this but there may be a small chance late tomorrow and into the night of some thunderstorms across East Anglia and up the east coast of Lincolnshire. The timing would indicate something possibly breaking out across EA late afternoon/early evening as and be around the Humber early hours of Friday morning. Anything that did develop would develop in an environment of 40knts DLS, moderate levels of helicity and lightning wizard indicates a low level supercell parameter along the Lincolnshire coast. ELT's around the coastline look quite promising in the early hours as does a build up of MUCAPE.

 

Caveats could be limited moisture, although this is shown to arrive overnight on the GFS.

 

Latest NMM does not support this idea. Although it shows some very decent CAPE across the SE and EA, it looks like ridging aloft prevents anything from forming and then by the time the moisture arrives from the west, the best CAPE is out to sea. NAE is not supporting of it either.

 

A bit further out but Fri night and into Saturday look interesting for western areas, especially bordering the coast. 

 

EDIT: Met Office and BBC show this scenario for late tomorrow too.

Edited September 4, 2013 by Supacell

[Guest William Grimsley]

There is a lovely line of altocumulus castellanus clouds to the N of here, now.

Edited September 4, 2013 by William Grimsley

[Convective]

Can see a line of altocumulus castellanus to the west over the Irish Sea.

 

Yes! Right over me but its gone so, so dark, heavy and extremely thundery now! Wouldn't surprise me tonight to be fair! One of them stray storms that no one forecasts!

 

 

 

[Skeggy Winter Storm]

Possibly a brave call this but there may be a small chance late tomorrow and into the night of some thunderstorms across East Anglia and up the east coast of Lincolnshire. The timing would indicate something possibly breaking out across EA late afternoon/early evening as and be around the Humber early hours of Friday morning. Anything that did develop would develop in an environment of 40knts DLS, moderate levels of helicity and lightning wizard indicates a low level supercell parameter along the Lincolnshire coast. ELT's around the coastline look quite promising in the early hours as does a build up of MUCAPE.Caveats could be limited moisture, although this is shown to arrive overnight on the GFS.Latest NMM does not support this idea. Although it shows some very decent CAPE across the SE and EA, it looks like ridging aloft prevents anything from forming and then by the time the moisture arrives from the west, the best CAPE is out to sea. NAE is not supporting of it either.A bit further out but Fri night and into Saturday look interesting for western areas, especially bordering the coast. EDIT: Met Office and BBC show this scenario for late tomorrow too.

That would be a nice way to end a half decent summer here weve only had one decent storm here this summer which was awesome and a few rumbles here and there not expecting anything but would be nice surprise anyways

[Guest William Grimsley]

 

Yes! Right over me but its gone so, so dark, heavy and extremely thundery now! Wouldn't surprise me tonight to be fair! One of them stray storms that no one forecasts!

 

 

 

 

Nice pics, Convective!